1. Field of the Invention
This invention relates to an apparatus for treating organic raw water utilizing anaerobic microorganisms and more particularly to an apparatus for treating raw water contained organic matter, or the like such as, living drainage, factory drainage, etc., by utilizing anaerobic microorganisms.
2. Prior Art
Japanese patent application No. 9-199208 (see counterpart U.S. Pat. No. 5,972,212) by the applicant relates to an apparatus of the type in which raw water is treated in circulation by aeration, and by aerobic microorganisms.
Also, known is an apparatus that eliminates, in the same treating times as usual with an activated silt method, bio-chemically nitrogen, phosphorus, etc. of raw water, by making higher the density of germs, by inserting in a bioreaction tank spherical or foamed cubic carriers for rooting microorganisms thereto.
The apparatus shown in Japanese patent application No. 9-199208 uses air and it cannot apply to a case where anaerobic microorganisms are used.
Spherical or foamed carriers become considerable in numbers, and it is very troublesome to treat same by washing or replacing.